Control for thermostatic valves



p 1941- c. F. HIRSHFELD 2,255,118

CONTROL FOR THERMOSTATIC VALVES Filed Jan. 20, 1939 INVENTOR. 1 9900; K J lemma-4 ATTORNEY.

- Patented Sept. 9; 1941 UNITED 'STATE CONTROL FOR THEBMQSTATIC VALVES Clarence F.

Transit Research New York Hirshfeld, Detroit, Mich assignor to Corporation, a corporation of Application January 20, 1939, Serial No. 251,893

2 Claims.

This invention relates to thermostatically operated valves and more particularly to the thermostatic element therefor and its environment, and has'for its object to provide a device of this kind of improved sensitiveness. I

In large valves, such, for example, as are used for operating ventilation dampers for rail vehicles, the chamber containing the temperature responsive fluid as now constructed is usually of heavy construction which, because of its mass, causes an unduly long lag in the responsiveness of the fluid. It is highly desirable to reduce the lag to an absolute'minimum in order that the thermostatic fluid will respond immediately to the temperature of the air or other surrounding medium to which it is exposed and which it is expected to control. It is, therefore, an object of this invention to provide a chamber which may be described as a separate capsule of thermostatic fluid together with assembly means for retaining the capsule in operative position of such construction as will provide a minimum heat path from the valve cage to the capsule.

More particularly it is an object to provide a thin-walled expansible capsule containing thermostatic fluid in combination with retaining means therefor against which said capsule reacts, said retaining means presenting a minimum surface to the capsule and being separated from direct contact therewith by pads having poor heat transmitting properties. Another object is to provide means for supporting a thermostatic capsule in an air stream between two surfaces of substantial mass which comprises a multiplicity of flngers of thin crosssection in combination with air deflecting and heat blocking surfaces which restrict the capsule against contact by air which has contacted said surfaces.

Other objects and advantages will become more fully apparent as reference is had to the accompanying drawing wherein my invention is illustrated, and in which:

Fig. 1 is a vertical section statically operated valve construction embodying my invention,

Fig. 2 is a top plan view thereof,

Fig. 3 is a horizontal section taken along the line 3-3 of Fig. 1 showing a capsule contacting member in plan view, and

Fig. 4 is an enlargened sectional detail of a plate projection with its insulating cap.

More particularly I indicates a fluid pressure line connected through a thermostat control valve device to a line 2 leading into a cylinder 3, which houses a piston L The piston is adapted to be moved in one direction by the pressure in the lines I and 2 and in the other direction by a spring 5. A piston rod 8 flxed to the piston is attached at its outer end ing a damper or any other suitable device or mechanism (not shown).

The control valve is composed of a housing 8 into the sidewalls of which the lines I and 2 are connected. The line I projects into this housing, is sealed at its end and has its'outlet at 9 in the side thereof. A valve carrier l0 resides within the housing 8 and is equipped with one valve H for opening and closing the port 9 and another valve l2 for opening and closing an outlet passage l3'by which the interior of the hous- 'ber [1 having guide holes It for the insertion ing 8 may be vented. A spring I4 urges the valves II and I2 toward their respective seats,

the pressure exerted by the spring being adjustable by means of a manually operable screw 15 which extends through the housing 8 and which carries the spring base 16.

The passage I3 is formed in a movable memtherethrough of guide rods I9 fixedly secured at one end 20 to the housing8 and at their other end to a relatively stationary member 2|.

Springs 22 encircling the rods l9 urge the movable member II with its passage l3 away from the housing 8.

In order to flexibly seal the space betweenthe member I! and the housing 8 a bellows 28 is interposed whereby the member I! may move as required by the expansion and contraction of a thin-walled metallic capsule 23. This capsule is fllled with'a suitable fluid, such as methyl chloride or butylene which boil under atmospheric pressures at 5 F. and 24 F., respectively, and

which have, at ordinary atmospheric temperatures, vapor pressures which are substantially higher than atmospheric pressure and which vary considerably with changes in temperature. This capsule is contained between a multiplicity of elongated projections or flngers 24 and 25 arising from the opposed surfaces of the members 2| and I1, respectively, being separated from each thereof by small pads 28 of flber, rubber or any other material having poor heat conducting properties, In Fig. 3 the large number and preferred orderly arrangement of the projections 24 is illustrated and it will be understood that there is a similar number of projections 25, similarly placed. Thecapsule 23 is held firmly against th pads 26 by pressure of the springs 22 which constantly urge the member I! toward the memto a lever I for operat-- her. 2| so that any movement of the capsule,

either of contraction or expansion, is immediately transmitted to the member llto cause movement thereof.

' The fluid, usually-air, to which the thermostatic element 26 is expected to respond flows ina. direction from left to right or vice versaas viewed in Fig. 1. Two bailles,21, preferably of thin material, pierced for the purpose are placed one -overthe projections 24 and the other over the a flow of fluid therepast for moving said members relatively, a plurality of projections of small cross-section arising from said members as spacer means between said element and said members,

- said l projections being regularly. spaced and'in the direct path 01 said fluid, and bailie means carried by the projections from both of said members intermediate their length for preventing contact with-said element of fluid which has,

contacted either of said members.

2. The combination in a. thermostatically controlled device of two relatively movable members of substantial heat retaining qualities, an element responsive to changes in temperature of a flow of fluid therepast for moving said members relatively, a plurality of projections of small cross-section arising from said members as spacer means between said element and said members,

said projections being regularly spaced and in the direct path of said fluid. and baflle means carried by the projections from both of said members intermediate their length for preventing contact with said element of fluid which has contacted either of said members, each-of said projections having a cap element composed of material of relatively poor heat transmitting quality.

CLARENCE F. Hmsmnn.

between its end and said 

